Nut-lock.



A. A. MACDONALD.

. NUT LOCK.

APPLICATION FILED AUG.'19,1911.

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NUT-LCCK.

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Specification of Letters Patent.

Patenten ren. ii, reis.

Application filed August 19, 1911. Serial No. 645,031. (Model.)

l the following is a Jfull, clear, and exact description.

lThis invention relates to improvements in lock nuts and bolts therefor, and the object is to provide asimple and inexpensive means by which nuts may be readily held against loosening on the bolts which carry them.

' A further object is'to provide a device of I this character having no additional parts or attachments, and so arranged that'either a nut or bolt may be' used with ordinary bolts or nuts.

A still further object is to provide a eooperating nut and bolt which will be as strong or stronger than the ordinary nuts and bolts.

Another object is to provide a nut so construete'd that when it'is forced off the bolt, it Willpress the bolt into such form that a nut maybe readily started by hand.

To accomplish these objects, I provide a bolt having the threaded end thereot` recessed, and sawed or otherwise separated into a plurality of fingers which may be ex- -panded by a suitable tool into a recess formed in the outer portion of the nut.-

This recess in the nut is so shaped that when the nut is forcibly removed from the bolt, it will compress the fingers sufliciently to allow a nut to be readily started on the threads of the bolt by hand.

In 'the drawings which illustrate this invention I--Figure l is a section al View showing the nut as screwed down on the bolt. Fig. 2 is asimilar View showing the fingers ot' the bolt expanded to lock the nut in place. Fig. 3 is a plan view of the nut with the bolt in place, the lingers being unexpanded. Fig. 4 is a similar view showing the bolt fingers expanded. Fig. 5 is a plan View ot a bolt as it appears after the nut has been -screwed oli. Fig. 6 is a plan view of the pointof a tool suitable for expanding the bolt fingers.

Referring to the drawings, 7 designates a pair of members' through which the bolt 8 passes, and which are held in place by the nut`9. The body and head of the bolt are of the usual form and may be made by any of the known processes. .The threaded end of' the bolt is formed into a plurality of fingers l0 by means of cuts ll extending diametrically through the bolt. At the point where these cuts 1l intersect, z'. e., the longitudinal axis of the bolt, a small hole l2 is formed, which hole preferably extends a short distance below the bottom of the cuts 1l, as seen in Figs. l and 2. The nut is of the usual external form and internally threaded to fit the bolt. The cuter portion of the nut is provided with a circular recessl 13 concentric with the bolt aperture. This recess..

is cylindrical or very nearly so for a short distance into the nut, as seen at 14:, and then converges in a curve until it meets the bolt aperture, as seen at 15.

In order that the nut may have the usual number of' threads engaging the bolt, it is made extra thick, the additional thickness being equal to the depth of the recess 13. lVhenthe nut is screwed into place on the bolt, the fingers l0`of the bolt lie within the recess of the nut, thus leaving a solid portion of the bolt engaging the threaded portion of the nut, so that there is no weakening ot' the bolt.

When in use, the bolt is placed in position and the nut screwed down tight in the usual manner. A suitable tool, shaped for instance as shown in Fig. 6, is introduced into the aperture 12 of the holt and driven in so as to expand the fingers 1C' to till the recess 13 in the nut. By reason of the sha eof the tool, the fingers are not merely ared outwardly but are pressed to conform to the interior of the recess. The reason for this particular shaping of the fingers is that when the nut is forcibly screwed off, t-he extremities of the fingers Will come together before the fingers are entirely straightened out, and thus leave the tip of the bolt slightly smaller than the usual diameter, so that4 a. nut may be readily started ony the threads by hand. It is obvious that if these fingers were merely flared out in a straight line, that when the nut Was forced ol thus compressing the lingers, there would be enough spring in the metal to cause the fingers to extend slightly, thus making the tip of the bolt slightly larger than normal so that great ditliculty would be experienced in starting another nut.

When Athe fingers are extended, as seen in Fig. 2, they will efiectually hold the nut against'evolution, as any revolution of the nut dile to vibration is `in a reverse or unserewing direction, which is also :in outward direction. Should the members 7 become worn under nut or bolt head, and thus loose, the nut may be tightened up in the usual manner and lockedin this tightened position, extending the fingers :i trifle more.

Having thus described my invention, I deelzue that what I claim is:-

`A device of the character described oomprising a bolt having the threaded end thereof split into a plurality of fingers, and

a-nut cooperating with said bolt having a recess in. the outer face thereof for the reception of the bolt fingers, said recess being substantially cylindrical at its outer end and converging in a curve at the bottom.

In witness whereof I have hereunto set my hand in the presence of two Witnesses.

ARCHBALD A. MACDONALD.

Witnesses:

STUART R, WV. ALLEN.

C. C. CARROLL. 

